Saw core VCO for Eurorack Modular synthesizers
This is a full featured SAW Core VCO. Sine, Pulse, Saw waveforms available with multiple modulation inputs and oscillator sync.
All waveforms are derived from a simple saw wave core using a JFET.
This VCO is compact, filling an 8HP space, but has comfortably spaced front panel controls for ease of operation.
Comprehensive documentation, parts lists are provided in the documentation link for building, testing and calibrating the module.
If you want a highly accurate tracking VCO, please ensure you use very well matched transistors and also glue the thermistor and the two transistors together. The slight differences in temperature coefficients of the transistors can make the oscillator difficult to tune. If you don't need a highly accurate oscillator, you can use any transistors and even use a resistor instead of the thermistor. Here's a comment from one of our builders of a similar VCO:
"I ended up swapping the transistors from some I got in a Mouser order
vs the ones I matched from a Chinese retailer. Found some that matched
less then 1mv difference and Low and behold, I can tune it now!" From Dayne, Grand Forks, BC.
The following video, courtesy of Randy Piscione, shows the VCO in action:
Module is available as a DIY project only.
This Module is a prototype or in a concept phase.$25 Price in € submitted Mar 14th 2019, 20:37 by jnfrench | last Change Jul 2nd 2019, 20:26 by jnfrench
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